1. Field of the Invention
The present invention relates in general to an ocular iontophoretic device, and more particularly, to an ocular iontophoretic device which, upon association with the eye of a living being, and application of an electrical potential difference, iontophoretically delivers an interferon into the living being""s eye, thereby treating viral, immunoregulatory, and/or neovascularization conditions.
2. Background Art
Interferons have been known in the art for years, and have been shown to possess antiviral as well as immunoregulatory activities. More recently, research has been initiated relative to treating numerous conditions characterized by or arising from neovascularization in the tissues and structures of the eye, including Age-Related Macular Degeneration (AMD). While administering an interferon has been identified as a promising mechanism to remedy the above-identified conditions, delivering an interferon to an affected area of a living being""s eye remains problematic. Indeed, known prior art devices and associated methods of administering an interferon, identified hereinbelow, are replete with drawbacks and disadvantages.
For example, delivering an interferon to an affected, local area of a living being""s eye using a systemic delivery method is problematic because of the many conventional side effects associated with systemic delivery, including depression, headache, arthritis-like joint pain, flu-like symptoms, unnecessary medicament exposure to unaffected areas, toxicity buildup, and concentration control.
Local delivery of an interferon via interocular injection is problematic because of the opportunity for, among other things, retinal detachment, bleeding into the interior of the eye, increased interocular pressure, and increased risk of secondary infection. Although perhaps justifiable for occasional acute conditions, these risk factors render interocular injection undesirable as a delivery mode for chronic administration. Furthermore, interocular injections can be scary, unpleasant, and painful for the patient.
In addition to the above-identified problems associated with interocular injection, peribular or subconjuctival injection of an interferon is problematic, because such injections may not deliver sufficient quantities to the interior of the eye. Moreover, peribular or subconjuctival injections are demanding of the physician inasmuch as placement of the needle requires an extremely high level of precision.
Topical administration of an interferon to an affected, local area of a living being""s eye is problematic due to its ineffectiveness for many applications, including affected areas in the back of the eye.
The present invention is directed to an ocular iontophoretic device for delivering an interferon to an affected area of a living being""s eye comprising an active electrode assembly associated with a matrix, wherein the matrix includes an interferon capable of treating viral, immunoregulatory, and/or neovascularization conditions.
In a preferred embodiment of the present invention, the matrix includes an interferon selected from the group consisting of an alpha-interferon, a beta-interferon, a gamma-interferon, and mixtures thereof. In this embodiment the interferon may include a single type of beta-interferon, such as beta-1b interferon.
In another preferred embodiment of the present invention, the interferon comprises one or more natural or synthetic proteins having a molecular weight ranging from approximately 15,000 to approximately 25,000 daltons.
In yet another preferred embodiment of the present invention, the interferon is formulated in an approximately 20 mM sodium acetate and approximately 208 mM arginine hydrochloride buffer. In this embodiment the buffer may range in pH from approximately 4.0 to approximately 6.0, and more preferably from approximately 4.5 to approximately 5.0.
Preferably, the affected area of the eye is selected from at least one of the group consisting of the vitreous humor, retina, choroid, circulation of the retina, circulation of the choroid, and sclera.
In accordance with the present invention, the ocular iontophoretic device further comprises a counter electrode assembly, wherein the counter electrode assembly is configured for completing an electrical circuit between the active electrode assembly and an energy source, and an energy source for generating an electrical potential difference.
The present invention is also directed to an ocular iontophoretic device for delivering an interferon to an affected area of a living being""s eye, comprising: (a) a matrix, wherein the matrix is capable of temporarily retaining a solution having an interferon; (b) an active electrode assembly associated with the matrix, wherein the active electrode assembly is configured for iontophoretically delivering the interferon to the affected area of the living being""s eye; (c) a counter electrode assembly, wherein the counter electrode assembly is configured for completing an electrical circuit between the active electrode assembly and an energy source; and (d) an energy source for generating an electrical potential difference. It is also contemplated that the ocular iontophoretic device comprise a reservoir, wherein the reservoir includes an interferon capable of treating viral, immunoregulatory, and/or neovascularization conditions.
The present invention is further directed to a method for treating an affected area of a living being""s eye comprising the steps of: (a) associating an interferon with an ocular iontophoretic device; (b) positioning at least a portion of the ocular iontophoretic device on the eye of a living being; and (c) and iontophoretically delivering the interferon to an affected area of the living being""s eye.
In a preferred embodiment of the present invention, the step of associating the interferon includes the step of associating an interferon capable of treating viral, immunoregulatory, and/or neovascularization conditions.
In another preferred embodiment of the present invention, the step of iontophoretically delivering the interferon includes the step of iontophoretically delivering the interferon to at least one of the group consisting of the vitreous humor, retina, choroid, circulation of the retina, circulation of the choroid, and sclera.
In yet another preferred embodiment of the present invention, the step of iontophoretically delivering the interferon includes the step of iontophoretically loading a sclera of the living being""s eye with the interferon for prolonged delivery into back regions of the living being""s eye.
Preferably, the step of iontophoretically delivering the interferon, includes the step of iontophoretically delivering the interferon at a current between approximately 0.5 mA and approximately 4 mA for a period of between approximately 5 and approximately 20 minutes.
In accordance with the present invention, the step of iontophoretically delivering the interferon includes the step of delivering the interferon using positive polarity electrical current.
In a preferred embodiment of the present invention, the step of positioning at least a portion of the ocular iontophoretic device on the eye of a living being includes the step of applying at least a portion of the ocular iontophoretic device to a conjunctival surface in a region of a pars planum and insertions of an anterior cilliary artery.
The present invention is further directed to a method for treating a viral, immunoregulatory, and/or neovascularization condition within an affected area of a living being""s eye comprising the steps of: (a) associating an interferon with a matrix of an ocular iontophoretic device; (b) associating the ocular iontophoretic device having an active electrode assembly with the eye of the living being; (c) iontophoretically delivering an effective amount of the interferon to an affected area of the living being""s eye having a viral, immunoregulatory, and/or neovascularization condition; and (d) treating the affected area of the living being""s eye, and, in turn, reducing or eliminating effects of a viral, immunoregulatory, and/or condition.